CN112334259A

CN112334259A - Reamer bit

Info

Publication number: CN112334259A
Application number: CN201980043581.8A
Authority: CN
Inventors: 田中作弥; 泽孝治
Original assignee: ALMT Corp
Current assignee: ALMT Corp
Priority date: 2018-06-28
Filing date: 2019-04-03
Publication date: 2021-02-05
Also published as: JPWO2020003679A1; MX2020013112A; US11724323B2; WO2020003679A1; US20210245276A1; JP6697131B1; US20230347427A1

Abstract

The reamer of the present invention is provided with a core and a plurality of peripheral cutting edges made of a hard tool material and provided on the outer periphery of the core. The core extends from a front end to a rear end. The core is provided with a plurality of chip flutes extending from the front end to the rear end. A relief portion is provided in at least a part of a region between a tip end of the chip pocket to a rear end of the core as a center of gravity adjustment portion for adjusting misalignment of the center of gravity and the center of rotation. Due to the gravity center adjusting portion, the misalignment of the gravity center with the rotation center is smaller than in the case where the gravity center adjusting portion is not provided.

Description

Reamer bit

Technical Field

The present invention relates to reamers. This application claims priority based on japanese patent application No.2018-123495, filed 2018, month 6, 28, the entire contents of which are incorporated herein by reference.

Background

Conventionally, reamers have been disclosed in PTL1 (japanese patent laid-open No. 2006-.

CITATION LIST

Patent document

PTL 1: japanese patent laid-open No.2006-88242

PTL 2: japanese patent publication No.2011-62790

PTL 3: japanese patent laid-open No.2016-32863

Disclosure of Invention

A reamer according to an aspect of the present invention includes a core portion and a plurality of peripheral cutting edges provided on an outer periphery of the core portion and made of a hard tool material, the core portion extending from a front end to a rear end, the core portion being provided with a plurality of chip flutes extending from the front end to the rear end, a center of gravity adjusting portion being provided at least partially from a tip of the plurality of chip flutes located on the rear end side to the rear end of the core portion, the center of gravity adjusting portion adjusting a distance from a center of rotation to the center of gravity, the center of gravity adjusting portion making the distance from the center of rotation to the center of gravity smaller than that when the center of gravity adjusting portion is not provided.

Drawings

Fig. 1 is a front view of a reamer according to embodiment 1.

Fig. 2 is a plan view of the reamer as viewed from the direction indicated by the arrow II in fig. 1.

Fig. 3 is a bottom view of the reamer as viewed from the direction indicated by arrow III in fig. 1.

Fig. 4 is a perspective view of a reamer according to example 1.

Fig. 5 is a left side view of the reamer as viewed from the direction indicated by arrow V in fig. 1.

Fig. 6 is a right side view of the reamer as viewed from the direction indicated by arrow VI in fig. 1.

Fig. 7 is a sectional view taken along line VII-VII in fig. 1.

Fig. 8 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 7.

Fig. 9 is a sectional view taken along line IX-IX in fig. 1.

Fig. 10 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 9.

Fig. 11 is a sectional view taken along line XI-XI in fig. 1.

Fig. 12 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 11.

Fig. 13 is a sectional view taken along line XIII-XIII in fig. 1.

Fig. 14 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 13.

Fig. 15 is a front view of a reamer according to embodiment 2.

Fig. 16 is a plan view of the reamer as viewed from the direction indicated by the arrow XVI in fig. 15.

Fig. 17 is a bottom view of the reamer as viewed from the direction indicated by the arrow XVII in fig. 15.

Fig. 18 is a perspective view of a reamer according to example 2.

Fig. 19 is a left side view of the reamer as viewed from the direction indicated by arrow XIX in fig. 15.

Fig. 20 is a sectional view taken along line XX-XX in fig. 15.

Fig. 21 is a sectional view taken along line XXI-XXI in fig. 15.

Fig. 22 is a sectional view taken along line XXII-XXII in fig. 15.

Fig. 23 is a plan view of a workpiece provided with a hole.

Fig. 24 is a sectional view of a workpiece provided with a hole.

Detailed Description

[ problem to be solved by disclosure of the invention ]

Conventional reamers may not reduce the cylindricity and roundness of the workpiece.

The present invention has been made to solve the above problems, and therefore it is an object of the present invention to provide a reamer capable of reducing the cylindricity and roundness of a workpiece.

[ effects of disclosure of the invention ]

The invention can provide a reamer capable of reducing the cylindricity and roundness of a workpiece.

[ description of embodiments of the invention ]

First, embodiments of the present invention are enumerated and described.

In the reamer configured as described above, the center of gravity adjusting portion that adjusts the position of the center of gravity from the rotation center is provided at least partially from the tip of the plurality of chip flutes on the rear end side to the rear end of the core portion, and the center of gravity adjusting portion is provided at such a portion, and therefore is positioned so as not to contact the workpiece at the time of cutting. This enables the center of gravity to be adjusted without affecting the cutting performance.

Preferably, the center of gravity adjusting part is a tip of the plurality of chip flutes, wherein the tip is disposed at different positions in the axial direction. In this case, the center of gravity adjusting portion may be formed by providing the ends of the plurality of chip flutes at different positions. This can provide the center of gravity adjusting portion in a simple configuration.

Preferably, the center of gravity adjusting portion is a relief portion provided at a tip of one of the plurality of chip flutes. In this case, the center of gravity adjusting portion may be provided by removing only a part of the material of the core portion.

Preferably, the core has a shank held by the machine tool, and the center of gravity adjusting portion is provided in the shank. In this case, since the holder is provided with the center of gravity adjusting portion, the center of gravity adjusting portion can be provided at various positions in the holder, thereby improving the degree of freedom in design.

Preferably, the plurality of peripheral cutting edges have first to third peripheral cutting edges adjacent to each other, and a phase difference between the first and second peripheral cutting edges is smaller than a phase difference between the second and third peripheral cutting edges. In this case, although the first to third cutting edges are arranged at irregular intervals, and thus the center of gravity is easily deviated from the center of rotation, the center of gravity may be adjusted by the center of gravity adjusting part.

Preferably, the center of gravity adjusting portion is provided at a phase corresponding to between the first peripheral cutting edge and the second peripheral cutting edge. In this case, the center of gravity is likely to be shifted between the first and second cutting edges because the phase between the first and second cutting edges is small, but the center of gravity can be adjusted by the center of gravity adjusting portion provided at the phase corresponding to the phase between the first and second cutting edges.

(example 1)

Fig. 1 is a front view of a reamer according to embodiment 1. Fig. 2 is a plan view of the reamer as viewed from the direction indicated by the arrow II in fig. 1. Fig. 3 is a bottom view of the reamer as viewed from the direction indicated by arrow III in fig. 1. Fig. 4 is a perspective view of a reamer according to example 1. Fig. 5 is a left side view of the reamer as viewed from the direction indicated by arrow V in fig. 1.

As shown in fig. 1 to 5, the reamer 90 includes a core 80 and a plurality of peripheral cutting edges 11 to 15, the peripheral cutting edges 11 to 15 being provided on the outer periphery of the core 80 and made of diamond or CBN, which is a hard tool material. The core 80 extends from the forward end 82 to the rearward end (shank 87) of the reamer 90. The core 80 is provided with a plurality of chip flutes 21 to 25 from a front end 82 to a rear end of the core 80. From the tip of the chip pocket 21 on the rear end side to the rear end of the core 80, a relief portion 29 serving as a center of gravity adjusting portion that adjusts the deviation of the center of gravity position from the center of rotation is provided at least partially. The center of gravity adjusting part makes the deviation of the center of gravity from the rotation center smaller than that when the center of gravity adjusting part is not arranged.

In the present embodiment, the tool shank 87 has a cylindrical shape, but may have any other shape, such as a rectangular cylindrical shape, a truncated conical shape, or a truncated pyramidal shape.

In the present embodiment, the chip flutes 21 to 25 extend straight parallel to the axis of rotation. However, the chip flutes 21 to 25 may extend curvilinearly. In addition, the chip flutes 21 to 25 may extend linearly while being inclined toward the rotation axis.

Flutes

21 and 23 each have a length L1, with length L1 being greater than length L2 of flute 24.

An area having a predetermined length from the leading end 82 of the reamer 90 is a cutting edge effective area 80a, an area of the reamer 90 on the rear end side is a chuck (chuck) area 80c, and an area between the two areas is a balance adjustment area 80 b.

In the present embodiment, the angle between the peripheral cutting edge 11 and the peripheral cutting edge 12 is 60 °, the angle between the peripheral cutting edge 12 and the peripheral cutting edge 13 is 60 °, the angle between the peripheral cutting edge 13 and the peripheral cutting edge 14 is 60 °, the angle between the peripheral cutting edge 14 and the peripheral cutting edge 15 is 90 °, and the angle between the peripheral cutting edge 15 and the peripheral cutting edge 11 is 90 °. However, angles other than these angles may be provided.

The hard tool insert 19 has peripheral cutting edges 11 to 15 and lands 18, each land 18 being provided on the rear side of a corresponding one of the peripheral cutting edges 11 to 15 in the rotational direction. The land 18 is the portion that contacts the workpiece during rotary cutting. Referring to fig. 2, the margin 18 is formed by a hard tool insert 19 and a block. However, the margin 18 may be formed by only the hard tool insert 19.

Fig. 6 is a right side view of the reamer as viewed from the direction indicated by arrow VI in fig. 1. As shown in fig. 6, the core portion 80 is provided with oil holes 81. The oil holes 81 extend in the axial direction of the core portion 80.

Fig. 7 is a sectional view taken along line VII-VII in fig. 1. Fig. 8 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 7. As shown in fig. 7 and 8, the center of gravity 86 in the cross section is offset in the x-axis direction and the y-axis direction from the rotation center 85 as the rotation axis. In this cross section, the center of gravity is offset toward the peripheral cutting edges 11 to 13. This is because the proportion of the core 80 is large on the side where the peripheral cutting edges 11 to 13 are provided.

Fig. 9 is a sectional view taken along line IX-IX in fig. 1. Fig. 10 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 9. As shown in fig. 9 and 10, the center of gravity 86 in the cross section is offset from the center of rotation 85 in the x-axis direction and the y-axis direction. In this section, the center of gravity deviates toward the chip flutes 21 to 23. This is because the proportion of the core 80 is greater on the side where the chip flutes 21 to 23 are provided.

Fig. 11 is a sectional view taken along line XI-XI in fig. 1. Fig. 12 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 11. As shown in fig. 11 and 12, the center of gravity 86 in the cross section is offset from the center of rotation 85 in the x-axis direction and the y-axis direction. In this cross section, the center of gravity is shifted toward chip pocket 24 for the following reasons. Since the relief 29 is formed and the chip flute 24 is small, the proportion of the core 80 on the chip flute 24 side is large.

Fig. 13 is a sectional view taken along line XIII-XIII in fig. 1. Fig. 14 shows the deviation of the center of gravity of the reamer from the center of rotation in the cross-section shown in fig. 13. As shown in fig. 13 and 14, the center of gravity 86 of the cross section deviates from the center of rotation 85 in the x-axis direction and the y-axis direction. In this cross section, the center of gravity 86 is offset opposite to the lightening 29. Although the relief 29 is a portion having a smaller rotation diameter than that of its surrounding portion, the relief 29 is different from the chip grooves 21 to 25. The chip flutes 21 to 25 have a chip removing function, while the relief 29 does not. The relief 29 may be a curved surface or a flat surface (zero curvature).

In embodiment 1, the center of gravity adjusting portions are the tips of the chip flutes 21 to 25 disposed at different positions in the axial direction. In other words, the center of gravity adjusting portion may also be configured by disposing the tips (e.g., 21a) of the chip pockets 21 to 25 at different positions without the lightening portion 29.

The peripheral cutting edges 11 to 15 have first to third peripheral cutting edges 12, 11, 15 adjacent to each other, and the phase difference between the first and second peripheral cutting edges 12, 11 is smaller than the phase difference between the second and third peripheral cutting edges 11, 15. The relief portion 29 is provided at a phase corresponding to between the peripheral cutting edges 11, 12.

(example 2)

Fig. 15 is a front view of a reamer according to embodiment 2. Fig. 16 is a plan view of the reamer as viewed from the direction indicated by the arrow XVI in fig. 15. Fig. 17 is a bottom view of the reamer as viewed from the direction indicated by the arrow XVII in fig. 15. Fig. 18 is a perspective view of a reamer according to example 2. Fig. 19 is a left side view of the reamer as viewed from the direction indicated by arrow XIX in fig. 15.

As shown in fig. 15 to 19, the reamer 90 includes a core 80 and peripheral cutting edges 11 to 15, which are provided on the outer periphery of the core 80 and are made of diamond or CBN, which is a hard tool material. The core 80 extends from the forward end 82 to the rearward end (shank 87) of the reamer 90. The core 80 is provided with chip flutes 21 to 25 from a front end 82 to a rear end of the core 80. In a part of the shank 87, from the end 21a of the chip pocket 21 on the rear end side to the rear end of the core 80, a hole 87a serving as a center of gravity adjusting portion that adjusts the deviation of the center of gravity position from the rotation center is provided at least partially. The center of gravity adjusting part makes the deviation of the center of gravity from the rotation center smaller than that when the center of gravity adjusting part is not arranged.

Fig. 20 is a sectional view taken along line XX-XX in fig. 15. Fig. 21 is a sectional view taken along line XXI-XXI in fig. 15. Fig. 20 and 21 correspond to fig. 7 and 9, respectively.

Fig. 22 is a sectional view taken along line XXII-XXII in fig. 15. As shown in fig. 22, the shank 87 is provided with a hole 87 a. The hole 87a lightens the portion where the hole 87a is provided, and therefore, the center of gravity is deviated in opposition to the hole 87 a.

The core 80 has a shank 87 held by a machine tool, and the shank 87 is provided with a hole 87a serving as a center of gravity adjusting portion.

Comparative example machining of aluminum alloy with polycrystalline Diamond

[ Table 1]

First, the reamer 90 (sample 1 and sample 2) having the shape of the reamer 90 of example 1 without the relief portion 29 was prepared. The core 80 is made of cemented carbide. The hard tool insert 19 is made of polycrystalline diamond.

The eccentricity amount of the reamer 90 (the distance from the rotation axis to the position of the center of gravity of the reamer 90) is measured.

The eccentricity amount is measured as follows. First, a reamer is attached to a high precision tool balancer. One example of a high precision tool balancer is the tool dynamic TD comfort balancer available from Hanmer (HAIMER).

When the reamer 90 is rotated, an unbalanced number is displayed. For example, 14.3gmm is shown. The mass of the reamer 90 was measured. For example, assume that the mass of the reamer is 200 g. The eccentricity can be obtained by dividing the unbalance by the mass of the tool. In the above example, the eccentricity is 14.3gmm/200 g-0.0715 mm.

Samples 1 and 2 had the eccentricity shown in table 1.

Subsequently, working tests were performed using sample 1 and sample 2. Fig. 23 is a plan view of a workpiece provided with a hole. Fig. 24 is a sectional view of a workpiece provided with a hole. As shown in fig. 23 and 24, first, a hole 101 is formed in a workpiece 100(ADC12(JIS H53022006)) with a drill. The hole 101 was machined using the reamer 90 as sample 1 and sample 2, thereby forming a finished hole 102. Table 2 shows the conditions for making the finished hole 102.

[ Table 2]

The roundness and cylindricity of the finished hole 102 were measured as specified in JIS B0621(1984) using a roundness and cylindricity measuring instrument (e.g., RONDCOM 65A available from Tokyo Seimitsu co., LTD.). The measurement data are values measured by a Minimum Zone Circle (MZC) method. Table 1 shows the results.

Table 3 shows the contents of evaluation criteria (AA, a, B) for roundness and cylindricity in table 1.

[ Table 3]

(example: processing of aluminum alloy with polycrystalline Diamond)

A reamer 90 having a relieved portion 29 in the shape of the reamer 90 of example 1 was prepared (samples 3 to 6 in table 1). The core 80 is made of cemented carbide. The hard tool insert 19 is made of polycrystalline diamond.

The eccentricity amount of the reamer 90 (the distance from the rotation axis to the position of the center of gravity of the reamer 90) is measured. Table 1 shows the amount of eccentricity.

Subsequently, working tests were performed using samples 3 to 6. As shown in fig. 23 and 24, first, a hole 101 is formed in a workpiece 100(ADC12(JIS H53022006)) with a drill. The holes 101 were machined using the reamers 90 as samples 3 to 6, thereby forming finished holes 102. Table 2 shows the conditions for making the finished hole 102.

The roundness and cylindricity of the finished hole 102 are measured. Table 1 shows the results.

As shown in table 1, in samples 3 to 6 provided with the lightening portions, the eccentricity was 0.05mm or less, and therefore, the roundness and cylindricity were evaluated as "a" or "AA". In contrast, it was found that in sample 1 and sample 2 having no reduced portion, the eccentricity was more than 0.05mm, and therefore, both the roundness and cylindricity were evaluated as "B".

Comparative example cast iron was processed with CBN sintered body

[ Table 4]

A reamer 90 (sample 7 and sample 8) having the shape of the reamer 90 of example 1 without the relief 29 was prepared. The core 80 is made of cemented carbide. The hard tool insert 19 is made of a CBN sintered body.

Samples 7 and 8 had the eccentricity shown in table 4.

Subsequently, processing tests were performed using sample 7 and sample 8. Fig. 23 is a plan view of a workpiece provided with a hole. Fig. 24 is a sectional view of a workpiece provided with a hole. As shown in fig. 23 and 24, first, a hole 101 is formed in a workpiece 100(FC250(JIS G55011995)) with a drill. The hole 101 was machined using the reamer 90 as sample 7 and sample 8, thereby forming a finished hole 102. Table 5 shows the conditions for making the finished hole 102.

[ Table 5]

The roundness and cylindricity of the finished hole 102 were measured using a roundness and cylindricity measuring instrument (for example, RONDCOM 65A available from tokyo precision corporation) in accordance with the specifications of JIS B0621 (1984). The measured data are values measured by the MZC method. Table 4 shows the results.

Table 6 shows the contents of evaluation criteria (AA, a, B) for roundness and cylindricity in table 4.

[ Table 6]

(example: processing of cast iron with CBN sintered body)

A reamer 90 having a relieved portion 29 in the shape of the reamer 90 of example 1 (samples 9 to 12 in table 4) was prepared. The core 80 is made of cemented carbide. The hard tool insert 19 is made of a CBN sintered body.

The eccentricity amount of the reamer 90 (the distance from the rotation axis to the position of the center of gravity of the reamer 90) is measured. Table 4 shows the amount of eccentricity.

Subsequently, working tests were performed using samples 9 to 12. As shown in fig. 23 and 24, first, a hole 101 is formed in a workpiece 100(FC250(JIS G55011995)) with a drill. The holes 101 were machined using the reamers 90 as samples 9 to 12, thereby forming finished holes 102. Table 5 shows the conditions for making the finished hole 102.

The roundness and cylindricity of the finished hole 102 are measured. Table 4 shows the results.

As shown in table 4, in samples 9 to 12 provided with the lightening portions, the eccentricity was 0.05mm or less, and therefore, the roundness and cylindricity were evaluated as "a" or "AA". In contrast, it was found that in sample 7 and sample 8 having no reduced portion, the eccentricity was more than 0.05mm, and therefore, both the roundness and cylindricity were evaluated as "B".

It should be understood that the embodiments and examples disclosed herein are illustrative and not restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the embodiments and examples described above, and is intended to include any modifications within the meaning and scope equivalent to the terms of the claims.

List of reference numerals

11. 12, 13, 14, 15: a peripheral cutting edge; 18: a margin; 19: a hard tool insert; 21. 22, 23, 24, 25: a chip pocket; 21 a: a terminal end; 29: a lightening part; 80: a core; 80 a: an edge active area; 80 b: a balance adjustment area; 80 c: a chuck region; 81: an oil hole; 82: a front end; 85: a center of rotation; 86: a center of gravity; 87: a knife handle; 87a, 101: an aperture; 90: a reamer; 100 workpieces; 102: and (5) finishing holes.

Claims

1. A reamer, comprising:

a core; and

a plurality of peripheral cutting edges provided on the outer periphery of the core and made of a hard tool material,

the core extends from a front end to a rear end,

the core is provided with a plurality of chip flutes extending from the front end to the rear end,

a center-of-gravity adjusting portion that adjusts a distance from a center of rotation to a center of gravity is provided at least partially from a tip of the plurality of chip flutes on a rear end side to the rear end of the core portion,

the center of gravity adjusting portion makes a distance from the rotation center to the center of gravity smaller than a distance from the rotation center to the center of gravity when the center of gravity adjusting portion is not provided.

2. The reamer of claim 1 wherein the center of gravity adjustment is the tip of the plurality of flutes, the tip being disposed at different positions in an axial direction.

3. The reamer according to claim 1 or 2, wherein the center of gravity adjustment portion is a relief provided at a tip of one of the plurality of chip flutes.

4. The reamer of any one of claims 1 to 3, wherein,

the core has a shank held by a machine tool, and

the gravity center adjusting part is arranged in the knife handle.

5. The reamer of any one of claims 1 to 4, wherein,

the plurality of peripheral cutting edges have first to third peripheral cutting edges adjacent to each other, and

a phase difference between the first peripheral cutting edge and the second peripheral cutting edge is smaller than a phase difference between the second peripheral cutting edge and the third peripheral cutting edge.

6. The reamer of claim 5 wherein the center of gravity adjustment is disposed at a phase corresponding between the first and second peripheral cutting edges.